In a decision released Tuesday, Judge Rolf Treu cited Brown v. Board of Educationand other cases to rule that the extremely strict rules limiting how teachers are hired and fired disproportionately impacted the state’s poor and minority students, thereby depriving them of their right to an equal education.

The current ruling is a preliminary one preceding a final ruling, to be issued within a month. Treu has indicated that he will allow the law to remain in place, pending an inevitable appeal to California’s Supreme Court.

The case, Vergara v. California, was filed in 2012 by nine public school students, who argued that three aspects of the state’s labor laws on teachers were unconstitutional.

First, the state’s rule on tenure required the state to either grant or deny permanent employment to new teachers after only 18 months of experience. L.A. Unified School District Superintendent John Deasy was one of many who testified that the mandated timeframe was insufficient to evaluate the quality of new teacher hires.

Second, the lawsuit targeted the state’s rules on firing teachers, which made it nearly impossible to fire a teacher for bad performance once they had been given tenure. Out of 300,000 teachers in California, less than 100 have been removed from classrooms in the past decade, and firing a teacher can take years and cost millions of dollars.

Third, the lawsuit attacked the state’s seniority protections, which stated that any layoffs undertaken by the state’s schools must follow the “Last In, First Out” (LIFO) rule that eliminates teachers not based on need or ability, but simply based on how long they had worked.

The combined effect of all these laws, the plaintiffs argued, was to fill California’s schools with thousands of incompetent teachers who were impossible to remove. These teachers were disproportionately assigned to low-income schools with high minority populations, thereby creating an unequal educational reality. This, they argued, violated the equal protection clause in the California constitution.

Judge Treu agreed, ruling that the state’s protections for incompetent teachers were excessive “uber due process,” and that its LIFO rule amounted to an assertion that “the state has a compelling interest in the de factoseparation of students from competent teachers, and a like interest in the de facto retention of incompetent ones.”

“The logic of this position is unfathomable and therefore constitutionally unsupportable,” Treu wrote in his opinion. Treu also observed that the state’s policies had created a “Dance of the Lemons” — a phenomenon in which grossly incompetent teachers who cannot be fired are simply transferred repeatedly from school to school to mitigate outrage. This phenomenon primarily affected poorer students, Treu wrote.